The invention relates in general to munitions and in particular to guns that may fire caseless ammunition.
A gun such as, for example, a cannon, may fire either cased or caseless ammunition. A gun having a firing chamber for caseless ammunition may include an obturation assembly. The obturation assembly may seal the rear end of the firing chamber when a propellant charge is combusted to launch a projectile. On the other hand, for guns that fire cased ammunition, the sealing may be performed by the case of the ammunition itself, held in position by a breech block.
A conventional obturation assembly is described in U.S. Pat. No. 2,482,865, issued on Sep. 27, 1949 to Oliver. A conventional obturation assembly may include a spindle having a shaft and a mushroom shaped head, and an obturation set. The obturation set may include a resilient obturator pad for mating with and sealing against an obturation seat, an inner ring and two retaining (split) rings. The obturation seat may be defined by the rim of the mouth at the rear end of the firing chamber.
When the spindle is displaced axially relative to the barrel of the gun by the combustion of the propellant charge in the firing chamber, the obturator pad may deform radially outward into sealing engagement with the obturation seat. The retaining rings may limit the deformation of the obturator pad and may prevent extrusion of the obturator pad. The obturation assembly may be held in position by the breech block of the gun. The shaft of the spindle may extend through a hole in a carrier abutting the breech block.
A known method of removing the spindle from the gun may be time-consuming, may involve the removal of many other associated parts, and may require the use of specialized tools. Moreover, the method may be repetitive because the obturator pad and split rings may need to be removed every day for cleaning and for wear and damage inspection. Spindle removal may be accomplished by unscrewing a nut-type of component from the threaded breech end of a spindle.
Some spindle-retaining technology may be complex and may involve the use of many components. The spindle may be keyed to prevent it from turning and the spindle nut may have a flip key to keep it from unscrewing. Behind the face of the spindle may be an obturator pad assembly and then a breech block. The breech block may be held to the carrier by a nut-like component. Often, there may be other devices on the back of the carrier which may have to be removed to access the nut that holds the spindle. These other devices may also require reinstallation after the spindle is reinstalled. Consequently, removal of the traditional spindle may take several minutes.
There is a need for a quick-release spindle that may be rapidly removed and installed, with minimal involvement of other components.